If someone want to send me an invitation letter from Poland, what is the government institution responsible for that? And he can cancel it during visa process and put me in bad situation? And if I got ...

I'd like to visit Wieliczka salt mines and the Auschwitz KZ. Is it possible to visit both places the same day? How much time should I stay in each place? What trains/buses have to take from central ...

I am looking for transportation from Krakow to Prague.
The only requirement that I have is that it's limited in time, so I can plan it. Hitch-hiking is not a possibility.
I don't care much about the ...

Is there another place than the station to leave luggage in Gdansk, Poland?
I was in the station, and there were around 10 lockers all full. I am not sure if I was in the right place though. I am not ...